title: L-Leucinamide hydrogensquarate: spectroscopic and structural elucidation.
abstract: The hydrogensquarate [LeuNH(2)] (HSq) of L-leucinamide has been synthesized and its structure has been determined by single crystal X-ray diffraction. A three dimensional network is formed by hydrogen bonds with participation of the O=C-NH(2) function, the hydrogensquarate ion and the N(+)H(3) group [NH(2)...O=C((Sq)) (2.840 and 2.749 A), ((Sq))OH...O=C(NH(2)) (2.618 A), NH(3) (+)...O=C((Sq)) (3.246, 2.804 and 2.823 A)], respectively. A theoretical approximation of the electronic structure was carried out by means of ab initio UMP2 and MP2 level of theory at the 6-311++G** basis set. The IR-spectroscopic assignment in the solid-phase was obtained by linear-polarized IR-spectroscopy of oriented samples as colloid suspensions in a nematic host and application of the reducing-difference procedure for the interpretation of polarized IR-spectra.
authors.affiliation: Institut für Umweltforschung, Universität Dortmund, Otto-Hahn-Strasse 6, 44221, Dortmund, Germany.
authors.forename: Tsonko
authors.initials: T
authors.lastname: Kolev
authors.forename: Sonya
authors.initials: S
authors.lastname: Zareva
authors.forename: Heike
authors.initials: H
authors.lastname: Mayer-Figge
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
authors.forename: William S
authors.initials: WS
authors.lastname: Sheldrick
authors.forename: Bojidarka B
authors.initials: BB
authors.lastname: Koleva
mesh_terms: D003460:Crystallization; D003503:Cyclobutanes / Q000138:chemical synthesis* / Q000737:chemistry; D006860:Hydrogen Bonding; D007930:Leucine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D014961:X-Ray Diffraction
chemical_list: D003503:Cyclobutanes; D007930:Leucine; C013086:leucinamide